From 68ff74a3a62e6cddfc292498141a8712a5f84b03 Mon Sep 17 00:00:00 2001
From: Hadrien Charlanes <hadrien@variabl.io>
Date: Thu, 3 Jun 2021 11:53:04 +0200
Subject: [PATCH] feat: added exposure cap logic in calculateUserAccountData

---
 contracts/protocol/libraries/helpers/Errors.sol    |  1 +
 .../protocol/libraries/logic/GenericLogic.sol      | 14 +++++++++++---
 .../protocol/libraries/logic/ValidationLogic.sol   |  2 +-
 helpers/types.ts                                   |  2 ++
 4 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/contracts/protocol/libraries/helpers/Errors.sol b/contracts/protocol/libraries/helpers/Errors.sol
index 7314f43c..ccee2a7b 100644
--- a/contracts/protocol/libraries/helpers/Errors.sol
+++ b/contracts/protocol/libraries/helpers/Errors.sol
@@ -110,6 +110,7 @@ library Errors {
   string public constant VL_RESERVE_PAUSED = '86';
   string public constant LPC_CALLER_NOT_RISK_OR_POOL_ADMIN = '87';
   string public constant RC_INVALID_EXPOSURE_CAP = '88';
+  string public constant VL_COLLATERAL_EXPOSURE_CAP_EXCEEDED = '89';
 
   enum CollateralManagerErrors {
     NO_ERROR,
diff --git a/contracts/protocol/libraries/logic/GenericLogic.sol b/contracts/protocol/libraries/logic/GenericLogic.sol
index 381fe804..395300ee 100644
--- a/contracts/protocol/libraries/logic/GenericLogic.sol
+++ b/contracts/protocol/libraries/logic/GenericLogic.sol
@@ -47,10 +47,12 @@ library GenericLogic {
     uint256 reservesLength;
     uint256 normalizedIncome;
     uint256 normalizedDebt;
+    uint256 exposureCap;
     bool healthFactorBelowThreshold;
     address currentReserveAddress;
     bool usageAsCollateralEnabled;
     bool userUsesReserveAsCollateral;
+    bool exposureCapped;
   }
 
   /**
@@ -112,8 +114,14 @@ library GenericLogic {
         vars.userBalanceETH = vars.assetPrice.mul(vars.userBalance).div(vars.assetUnit);
 
         vars.totalCollateralInETH = vars.totalCollateralInETH.add(vars.userBalanceETH);
-
-        vars.avgLtv = vars.avgLtv.add(vars.userBalanceETH.mul(vars.ltv));
+        vars.exposureCap = currentReserve.configuration.getExposureCap();
+        vars.exposureCapped =
+          IERC20(currentReserve.stableDebtTokenAddress)
+            .totalSupply()
+            .add(IERC20(currentReserve.variableDebtTokenAddress).totalSupply())
+            .div(10**vars.decimals) >
+          vars.exposureCap;
+        vars.avgLtv = vars.avgLtv.add(vars.exposureCapped ? 0 : vars.userBalanceETH.mul(vars.ltv));
         vars.avgLiquidationThreshold = vars.avgLiquidationThreshold.add(
           vars.userBalanceETH.mul(vars.liquidationThreshold)
         );
@@ -132,7 +140,7 @@ library GenericLogic {
           IERC20(currentReserve.stableDebtTokenAddress).balanceOf(user)
         );
         vars.userDebtETH = vars.assetPrice.mul(vars.userDebt).div(vars.assetUnit);
-        vars.totalDebtInETH = vars.totalDebtInETH.add(vars.userDebtETH);         
+        vars.totalDebtInETH = vars.totalDebtInETH.add(vars.userDebtETH);
       }
     }
 
diff --git a/contracts/protocol/libraries/logic/ValidationLogic.sol b/contracts/protocol/libraries/logic/ValidationLogic.sol
index dab27950..14217e6d 100644
--- a/contracts/protocol/libraries/logic/ValidationLogic.sol
+++ b/contracts/protocol/libraries/logic/ValidationLogic.sol
@@ -480,7 +480,7 @@ library ValidationLogic {
       exposureCap == 0 ||
         ltv == 0 ||
         totalSupplyStableDebt.add(totalSupplyVariableDebt).div(10**reserveDecimals) < exposureCap,
-      Errors.VL_SUPPLY_CAP_EXCEEDED
+      Errors.VL_COLLATERAL_EXPOSURE_CAP_EXCEEDED
     );
   }
 
diff --git a/helpers/types.ts b/helpers/types.ts
index adcb8977..8cca7b81 100644
--- a/helpers/types.ts
+++ b/helpers/types.ts
@@ -184,6 +184,8 @@ export enum ProtocolErrors {
   LPC_CALLER_NOT_EMERGENCY_OR_POOL_ADMIN = '85',
   VL_RESERVE_PAUSED = '86',
   LPC_CALLER_NOT_RISK_OR_POOL_ADMIN = '87',
+  RC_INVALID_EXPOSURE_CAP = '88',
+  VL_COLLATERAL_EXPOSURE_CAP_EXCEEDED = '89',
 
   // old